DDT (Dichloro-diphenyl-trichloroethane) and chlordane are the organochlorine pesticides (OCPs) dangerous to human health and easily accumulate in biological tissues, used to control insects in crops, livestock and house protection. This study aimed to evaluate the toxicity of DDT, cis (alpha-chlordane), and trans (gamma-chlordane) on the growth of two crustaceans species Daphnia magna (D. magna) and Moina macrocopa (M. macrocopa) after 24 h and 48 h.
Vietnam Journal of Marine Science and Technology 2022, 22(1), 95–102 Vietnam Academy of Science and Technology Vietnam Journal of Marine Science and Technology journal homepage: vjs.ac.vn/index.php/jmst The impacts of some plant protection chemical OCPs on two crustacean species Daphnia magna and Moina macrocopa Tran Thi Thu Huong1,*, Nguyen Xuan Tong2, Le Hung Anh2, Le Van Hau3 Faculty of Environment, Hanoi University of Mining and Geology, Hanoi, Vietnam Institute of Environmental Science, Engineering and Management, Industrial University of Ho Chi Minh city, Ho Chi Minh city, Vietnam Department of Fisheries Biotechnology, Biotechnology Center of Ho Chi Minh city, Ho Chi Minh city, Vietnam * E-mail: huonghumg@gmail.com Received: 17 May 2021; Accepted: 30 September 2021 ABSTRACT DDT (Dichloro-diphenyl-trichloroethane) and chlordane are the organochlorine pesticides (OCPs) dangerous to human health and easily accumulate in biological tissues, used to control insects in crops, livestock and house protection This study aimed to evaluate the toxicity of DDT, cis (alpha-chlordane), and trans (gamma-chlordane) on the growth of two crustaceans species Daphnia magna (D magna) and Moina macrocopa (M macrocopa) after 24 h and 48 h Each test concentration selected individuals of each species and repeated experimental times, the study results showed that the 50% lethal concentration (LC50) of D magna and M macrocopa when exposed to DDT for 24 h were 20.8 μg.L-1 and 13.5 μg.L-1, respectively; after 48 h the value decreased to only 4.8 μg.L-1 and 1.7 μg.L-1 Similarly, LC50 values of cis (alpha-chlordane) on species after 24 h exposure were 12.4 μg.L-1 and 11.8 μg.L-1, respectively; after 48 h were 4.6 μg.L-1 and 4.9 μg.L-1 The calculation results of LC50 when exposed to trans (gamma-chlordane) of D magna and M macrocopa after 24 h are 17.6 μg.L-1 and 12.4 μg.L-1, respectively; after 48 h, it decreased to 3.8 μg.L-1 and 3.7 μg.L-1 (p < 0.05) The results of the acute toxicity assessment also indicated that M macrocopa was more sensitive to toxicity than D magna with the same test conditions Keywords: D magna, M macrocopa, LC50, DDT, chlordane, toxicity Citation: Tran Thi Thu Huong, Nguyen Xuan Tong, Le Hung Anh, and Le Van Hau, 2022 The impacts of some plant protection chemical OCPs on two crustacean species Daphnia magna and Moina macrocopa Vietnam Journal of Marine Science and Technology, 22(1), 95–102 https://doi.org/10.15625/1859-3097/17038 ISSN 1859-3097/© 2022 Vietnam Academy of Science and Technology (VAST) 95 Tran Thi Thu Huong et al./Vietnam Journal of Marine Science and Technology 2022, 22(1), 95–102 INTRODUCTION Organochlorine pesticides (OCPs) are persistent organic pollutants (POPs) that have obtained a significant concern worldwide due to their persistence, long-distance transport, and bioaccumulation [1], negative impacts on aquatic organisms, humans, the environment, and ecosystems Daphnia magna (D magna) and Moina macrocopa (M macrocopa) are two invertebrate crustaceans found in the most freshwater ecosystems over the world, directly affected by OCPs such as Dichloro-diphenyltrichloroethane (DDT), cis (alpha-chlordane) and trans (gamma-chlordane) According to the ECOTOX database, the most common species used in the standardized toxicity assessment include Ceriodaphnia dubia, D magna, D pulex, and other daphnids such as M macrocopa and M microra [2] These model organisms are susceptible to toxic chemicals and occupy a central position in the food chain [3] In addition, D magna and M macrocopa are indicator organisms with high environmental sensitivity and easy to identify and control toxic substances, so they are usually used as standard organisms for toxicity testing on a pilot scale Therefore, many previous studies have used D magna and M macrocopa to evaluate water quality and ecological toxicity [4–6] However, there is little information on the acute toxicity assessment of OCPs on two crustaceans D magna and M macrocopa, in Vietnam Several relevant published studies, such as those evaluating the acute toxicity of o,p’-DDT on fish Oryzias curvinotus embryos, had recorded lethal concentrations of 50% (LC50) of 0.0813 µg/L and 0.0406 µg/L at 24 h and 48 h, respectively, and these concentrations have a substantial impact on heart rate, organ malformations and eye edema [7] Another study showed that endosulfan - a pesticide OCPs caused morphological changes, affecting the growth and survival of D magna with LC50 values at 24 h and 48 h of 0.332 µg/L and 0.129 µg/L, respectively [8] This study was performed to fill in the lack of data regarding the acute effects of OCPs such as DDT, cis, and transchlordane on freshwater crustaceans 96 This study aims to determine the effects of OCPs, including DDT, cis, and transchlordane, on two crustaceans D magna and M macrocopa The experiments were conducted in a medium containing the toxin to estimate the concentration of LC50 MATERIAL AND METHOD Experimental organisms D magna was developed at the laboratory, Institute of Science, Technology, and Environmental Management Industrial University of Ho Chi Minh at 21 ± 2oC, and the light-dark cycle is 16 h:8 h with intensity lighting varied from 500–800 lux M macrocopa was obtained from the Center for Biotechnology in Ho Chi Minh and developed at 25 ± 2oC, and the light-dark cycle of 16 h:8 h in medium-hard water (medium) EPA [9] The food for the experimental organism was the unicellular algae Chlorella vulgaris, once every 2–3 days and cleaned weekly The experimental organisms (24 h of age) were not fed for 24 h before being collected for testing The medium used for the organism and the experiments was tap water filtered through a 0.45 µm polymembrane filter The dissolved oxygen concentration was between mg/L and mg/L with pH 7–8 The culture period for one generation was two weeks before testing Chemicals The OCPs selected for experiments include DDT, cis, and trans-chlordane derived from Sigma-Aldrich with high purity (≥ 97%) The chemicals were diluted into concentration ranges according to the Mexican Norm NMXAA-087-SCFI guidelines [10] Stock solutions were stored in dark glass with rough stoppers at 4oC to minimize the possibility of photodegradation Methodology Experimental setup Experiments were repeated four times in a 6-wells SPL tray (Korea) Each experimental well contains mL of OCPs, and the control sample well is absent of chemicals Nine individuals of D magna and M macrocopa (24 h of age) were exposed to Tran Thi Thu Huong et al./Vietnam Journal of Marine Science and Technology 2022, 22(1), 95–102 the chemical DDT at concentrations 0, 5, 10, 24, 30, 35 µg/L, and cis, trans-chlordane are 0, 4.5, 6.3, 9.2, 13.5, 19.8, 26 µg/L [11] The mortality rate at 24 h and 48 h exposure to the chemical were recorded and calculated The experimental setup steps are shown in Figure below: individuals D magnal/M macracopa (24 h of age) mL DDT/cis/trans-chlordane (test sample), filtered tap water (control sample) Repeat times Observe the number of death at 24 h and 48 h Calculation of LC50 Figure Experimental setup steps All experiments were done four times, and the data were calculated as mean ± SE 10 (standard error) by the JMP 13 with a significance level of p < 0.05 LC50 values at 24 h, 48 h, and p were calculated using the statistical probity with SPSS 20 software [12] RESULTS AND DISCUSSION Effects of DDT The results of the DDT toxicity assessment on D magna and M macrocopa after 24 h and 48 h are shown in Figure and Table Table showed that the LC50 values on D magna and M macrocopa when exposure to DDT was 20.8 μg/L and 13.5 μg/L at 24 h, respectively; After 48 h, the value decreased to only 4.8 μg/L and 1.7 μg/L (p < 0.05) The results showed that M macrocopa is more sensitive to DDT chemicals than D magna when exposed to the same concentration and time of testing After 24 h exposure to DDT concentrations of 0, 5, 10, 24, 30, 35 µg/L, the average mortality rate changed of 0, 22, 33, 33, 39, 50% for D magna and 0, 25, 36, 44, 58, 61% for M macrocopa, respectively (Figure 2a) These results proved that DDT caused the death of M macrocopa individuals higher than D magna from concentrations > 10 µg/L 10 a) b) D magna M macrocopa Số cá thể tử mortality vong Number of individuals Số cá thể tử vong Number of individuals mortality a a a b bc c c b 8 a bc ab bc d d b a b c d c cd c e d -1 -1 10 15 20 25 30 Concentrations (µg.L-1) Nồng độ (µg L-1) 35 40 10 15 20 25 30 35 40 -1 Concentrations Nồng độ (µg(µg.L L-1) ) Figure Variation in individual mortality of D magna and M macrocopa after 24 h (a) and 48 h (b) exposure to 0, 5, 10, 24, 30, and 35 g/L DDT 97 Tran Thi Thu Huong et al./Vietnam Journal of Marine Science and Technology 2022, 22(1), 95–102 Although there was a change in mortality between the two studied species, the value of 100% was recorded at the highest experimental concentration (35 µg/L) after 48 h, including 0, 3, 42, 50, 78, 83, 100% for D magna and 0, 25, 47, 56, 64, 75, 100% for M macrocopa (p < 0.05) (Figure 2b) Table Toxicity of OCPs to D magna and M macrocopa Chemicals Values of LC50 (µg/L) (n = 4) D magna M macrocopa 20.8 (19.5–22.2) 13.5 (12.4–14.7) 4.8 (4.4–5.2) 1.7 (1.2–2.2) 12.4 (11.8–13.0) 11.8 (11.2–12.6) 4.6 (4.4–4.9) 4.9 (4.6–5.2) 17.6 (16.7–18.5) 12.4 (11.8–13.0) 3.8 (3.5–4.1) 3.7 (3.4–4.0) Exposure time (h) 24 h 48 h 24 h 48 h 24 h 48 h DDT Cis-chlordane Trans-chlordance Note: Values in brackets represent lower and upper bounds with 95% confidence intervals Effect of cis-chlordane The LC50 results on D magna and M macrocopa after 24 h exposure with cischlordane were 12.4 μg/L and 11.8 μg/L, respectively; after 48 h, the rates were 4.6 μg/L and 4.9 μg/L (p < 0.05) (Table 1) When the exposure time is prolonged, the toxicity of the chemical increases and reduces the survivability of D magna and M macrocopa Figure shows the toxicity assessment results of cis-chlordane on D magna and M macrocopa at concentrations of 0, 4.5, 6.3, 10 9.2, 13.5, 19.8, and 26 μg/L After 24 h exposure with cis-chlordanc, the mortality rates of D magna and M macrocopa were 0, 14, 28, 36, 44, 50, 61% and 0, 6, 14, 25, 33, 39, 47%, respectively (Figure 3a) After 48 h, the maximum mortality rate was 100%, the specific values recorded of0, 36, 44, 53, 67, 81, 100% and 0, 36, 50, 50, 61, 69, 97% (p < 0.05) (Figure 3b) These results showed that the toxic effect of cis-chlordane on D magna was higher than M macrocopa under the same experimental conditions 10 a) D magna M macrocopa a a ab abc bc cd de cd a a Số cá thể tử vong Number of individuals mortality Số cá thể tử vong Number of individuals mortality b) ab bc cd de e e -1 b cd e d de bc bc b 15 20 cd cd f e -1 10 15 20 25 -1 Concentrations ) Nồng độ (µg.L (µg.L ) -1 30 10 25 30 -1 Concentrations Nồng độ (µg(µg.L L-1) ) Figure Theindividual mortality of D magna and M macrocopa varied after 24 h (a) and 48 h (b) exposure to 0, 4.5, 6.3, 9.2, 13.5, 19.8, and 26 μg/L pesticides cis-chlordane 98 Tran Thi Thu Huong et al./Vietnam Journal of Marine Science and Technology 2022, 22(1), 95–102 Effects of trans-chlordane The LC50 values on D magna and M macrocopa after 24 h exposure to transchlordane reached 17.6 µg/L and 12.4 µg/L, respectively; however, after 48 h, the values decreased to only 3.8 µg/L and 3.7 µg/L (p < 0.05) (Table 1) The LC50 values in this study indicated that M macrocopa is more sensitive to trans-chlordane than D magna when the exposure time is prolonged After 24 h exposure to 0, 4.5, 6.3, 9.2, 13.5, 19.8, and 26 µg/L trans-chlordane, the results showed that the mortality rate of D magna and 10 10 a) D magna M macrocopa Số individuals cá thể tử vong Number of mortality Số individuals cá thể tử vong Number of mortality a ab bcd cd d cd c d M macrocopa increased 0, 11, 19, 22, 28, 36, 42% and 0, 17, 22, 28, 33, 39, 50%, respectively(Figure 4a) After 48 h, the control sample still did not detect dead individuals, although, in the experimental sample, the mortality rate gradually increased with the results of 0, 50, 53, 75, 75, 83, 97% for D magna and 0, 47, 53, 64, 75, 83, 97% for M macrocopa (p < 0.05) (Figure 4b) The study results on chlordane isomers showed that cis-chlordane’s toxicity to D magna and M macrocopa is higher than trans-chlordane bc bc a ab e e b b bc a a ab b cd c c de e -1 b) d f -1 10 15 20 25 30 Concentrations-1(µg.L-1) Nồng độ (µg L ) 10 15 20 25 30 -1 Concentrations (µg.L ) -1 Nồng độ (µg L ) Figure The individual mortality of D magna and M macrocopa varied after 24 h (a) and 48 h (b) exposure to 0, 4.5, 6.3, 9.2, 13.5, 19.8, and 26 µg/L pesticides trans-chlordane DISCUSSION OCPs enter water bodies through dry and wet deposition from the air, accumulating in rivers, lakes, and global oceans [13], causing negative impacts on aquatic organisms The LC50 value recorded on D magna after 48 h exposure to DDT in this study was 4.8 µg/L, which was higher than the value in the study by Kuo et al., (2012) 1.4 µg/L [14] but lower than the value recorded in the study by MejíaSaavedra et al., (2005) 5.2 µg/L [15], by Ivorra et al., (2019) 260 µg/L [16] After 48 h of exposure to DDT, the LC50 value in this study with M macrocopa was 1.7 µg/L, much lower than the result recorded by Liu et al., (2008) 324 µg/L [6] Furthermore, when exposed to DDT, the LC50 value on Hyalella azteca crustacean was 0.17 µg/L, lower than the value in this study Due to the exposure time being prolonged up to 96 h, so the toxic effect of the chemical on the organism is also higher[17] Several studies about acute toxicity have reported that DDT affects the survivability of fish and fish embryos under laboratory conditions [18, 19] Evaluation of acute toxicity with o,p’-DDT on Oryzias curvinotus fish embryos recorded LC50 values at 24 h and 48 h of 0.0813 µg/L and 0.0406 µg/L, respectively 99 Tran Thi Thu Huong et al./Vietnam Journal of Marine Science and Technology 2022, 22(1), 95–102 [7] The present study results showed that the LC50 values on D magna after 24 h and 48 h exposure with cis-chlordane, and transchlordane, respectively, were 12.4 µg/L and 4.6 µg/L; 17.7 µg/L and 3.8 µg/L These results are lower than the values reported by Manar et al., (2009), 22.6 µg/L and 13.4 µg/L, respectively [20] Some authors also noted that chlordane affects not only the survival but also the body size and fertility of D magna [20, 21] In addition, the LC50 values on fish with cischlordane and trans-chlordane were recorded at 7.4 µg/L [22] and 70 µg/L, respectively[23] The results of the toxicological assessment with OCPs showed that they were capable of causing a 100% mortality rate in both crustaceans, including D magna and M macrocopa [24] The experimental conditions, such as chemicals [7], the exposure time to toxic substances (long or short) [25], were affected and toxic to aquatic organisms Thus, there is a close relationship between the surviability of organisms with the forms and concentrations of pesticides added to the environment CONCLUSIONS This study investigated the toxicity of DDT, cis, and trans-chlordane on two crustaceans D magna and M macrocopa The results showed that chlordane was more toxic on D magna (LC50 values at 24 h and 48 h were 12.4 µg/L and 4.6 µg/L for cis-chlordane; 17.6 µg/L and 3.8 µg/L for trans-chlordane, respectively) compared with DDT (28.8 µg/L and 4.8 µg/L, respectively) Evaluation results on M macrocopa also detected chlordane toxicity (LC50 values at 24 h and 48 h were 11.8 µg/L and 4.9 µg/L for cis-chlordane; 12.4 µg/L and 3.7 µg/L, for trans-chlordane, respectively) was higher than DDT (13.5 µg/L and 1.7 µg/L, respectively) with the same experimental conditions The results demonstrated that survival of both species decreased after exposure to DDT, cis, and trans-chlordane chemicals, in which M macrocopa was more sensitive to OCPs than D magna This study’s findings help improve understanding of the adverse effects of OCPs 100 on freshwater aquatic animals The results also serve as a reference database for performing toxicity tests against other crustaceans (these groups have optimal growth limits in aquatic ecology or marine environments) Acknowledgments: The authors would like to thank the Institute of Science, Technology and Environmental Management - Industrial University of Ho Chi Minh and the students’ enthusiastic support during the research Many thanks to the Biotechnology Center of Ho Chi Minh for providing M macrocopa in this study REFERENCES [1] Tan, L., He, M., Men, B., and Lin, C., 2009 Distribution and sources of organochlorine pesticides in water and sediments from Daliao River estuary of Liaodongbay, Bohai Sea (China) Estuarine, Coastal and Shelf Science, 84(1), 119–127 https://doi.org/10.1016/ j.ecss.2009.06.013 [2] USEPA, 2018 ECOTOX Knowledgebase https://cfpub.epa.gov/ecotox/, accessed June 18, 2018 [3] Czech, B., Jośko, I., and Oleszczuk, P., 2014 Ecotoxicological evaluation of selected pharmaceuticals to Vibrio fischeri and Daphnia magna before and after photooxidation process Ecotoxicology and environmental safety, 104, 247–253 https://doi.org/10.1016/ j.ecoenv.2014.03.024 [4] Arndt, D A., Moua, M., Chen, J., and Klaper, R D., 2013 Core structure and surface functionalization of carbon nanomaterials alter impacts to daphnid mortality, reproduction, and growth: acute assays not predict chronic exposure impacts Environmental Science & Technology, 47(16), 9444–9452 https://doi.org/10.1021/es4030595 [5] Niculescu, S P., Lewis, M A., and Tigner, J., 2008 Probabilistic neural networks modeling of the 48-h LC50 acute toxicity endpoint to Daphnia magna SAR and QSAR in Environmental Research, 19(7–8), 735–750 https://doi.org/ 10.1080/10629360802550556 Tran Thi Thu Huong et al./Vietnam Journal of Marine Science and Technology 2022, 22(1), 95–102 [6] Liu, X B., Xi, Y L., Wang, J X., and Hu, K., 2008 Acute toxicity of DDT and its effects on life table demography of Moina macrocopa Ying Yong Sheng tai xue bao= The Journal of Applied Ecology, 19(6), 1343–1348 [7] Huong, T T T., Tong, N X., Binh, N T., Anh, L H., and Hong, D T B., 2019 The impact of o, p-DDT pesticide toxicity on the development of fish embryo Oryzias curvinotus Tap chi Sinh hoc, 41(2se1&2se2), 337–344 [8] Tong, N X., and Huong, T T T., 2019 The impact of endosulfan pesticide toxicity on the growthof Daphnia magna Vietnam Journal of Science and Technology, 61(1), 21–25 [9] Weber, C I., 1993 Methods for measuring the acute toxicity of effluents and receiving waters to freshwater and marine organisms Environmental Monitoring Systems Laboratory, Cincinnati, Ohio (USA) United States Environmental Protection Agency [10] Secretaría de Economía, 2010 Norma Mexicana NMX-AA-087-SCFI-2010 Análisis de Agua-Evaluación de Toxicidad Aguda Con Daphnia Magna, Straus (Crustácea-Cladócera)-MÉTODO DE PRUEBA (Cancela a La NMX-AA087-SCFI-1995) Secretaría de Economía: Cuauhtémoc, Mexico, pp 39 [11] Cooney, J D., 1995 Freshwater tests In Fundamentals of aquatic toxicology: effects, environmental fate, and risk assessment, ed GM Hand pp 71–102 [12] Finney, D J., 1971 Probit analysis, Cambridge University Press Cambridge, UK pp 50–80 [13] IARC Working Group on the Evaluation of Carcinogenic Risk to Humans, 2018 DDT, Lindane, and 2,4-D; International Agency for Research on Cancer: Lyon, France; ISBN 978-92-832-0179-3 [14] Kuo, J N., Soon, A Y., Garrett, C., Wan, M T., and Pasternak, J P., 2012 Agricultural pesticide residues of farm runoff in the Okanagan Valley, British Columbia, Canada Journal of Environmental Science and Health, Part B, 47(4), 250–261 https://doi.org/ 10.1080/03601234.2012.636588 [15] Mejía‐Saavedra, J., Sánchez‐Armass, S., Santos‐Medrano, G E., Gonzáaaalez‐Amaro, R., Razo‐Soto, I., Rico‐Martínez, R., and Díaz‐Barriga, F., 2005 Effect of coexposure to DDT and manganese on freshwater invertebrates: pore water from contaminated rivers and laboratory studies Environmental Toxicology and Chemistry: An International Journal, 24(8), 2037–2044 https://doi.org/10.1897/04-438R.1 [16] Ivorra, L., Cardoso, P G., Chan, S K., Tagulao, K., and Cruzeiro, C., 2019 Environmental characterization of 4, 4′dichlorobenzophenone in surface waters from Macao and Hong Kong coastal areas (Pearl River Delta) and its toxicity on two biological models: Artemia salina and Daphnia magna Ecotoxicology and environmental safety, 171, 1–11 doi: 10.1016/j.ecoenv.2018.12.054 [17] Lotufo, G R., Landrum, P F., Gedeon, M L., Tigue, E A., and Herche, L R., 2000 Comparative toxicity and toxicokinetics of DDT and its major metabolites in freshwater amphipods Environmental Toxicology and Chemistry: An International Journal, 19(2), 368–379 https://doi.org/10.1002/etc.5620190217 [18] Ton, C., Lin, Y., and Willett, C., 2006 Zebrafish as a model for developmental neurotoxicity testing Birth Defects Research Part A: Clinical and Molecular Teratology, 76(7), 553–567 doi: 10.1002/bdra.20281 [19] Wu, L., Ru, H., Ni, Z., Zhang, X., Xie, H., Yao, F., Zhang, H., Li, Y., and Zhong, L., 2019 Comparative thyroid disruption by o, p’-DDT and p, p’-DDE in zebrafish embryos/larvae Aquatic Toxicology, 216, 105280 https://doi.org/10.1016/j.aquatox 2019.105280 [20] Manar, R., Bessi, H., and Vasseur, P., 2009 Reproductive effects and bioaccumulation of chlordane in Daphnia magna Environmental Toxicology and Chemistry: An International Journal, 101 Tran Thi Thu Huong et al./Vietnam Journal of Marine Science and Technology 2022, 22(1), 95–102 28(10), 2150–2159 https://doi.org/ 10.1897/08-564.1 [21] Hamir, S R and Leo, M L N., 2012 Pesticides CRC Press 662 p https://doi.org/10.1201/b11864 [22] Chlorinated Pesticide Standard, Safety Data Sheet According to Regulation (EC) No 453/2010 2015 [23] Lahens, L., Strady, E., Kieu-Le, T C., Dris, R., Boukerma, K., Rinnert, E., Gasperi, J., and Tassin, B., 2018 Macroplastic and microplastic contamination assessment of a tropical river (Saigon river, Vietnam) transversed by a developing megacity Environmental Pollution, 236, 661–671 doi: 10.1016/j.envpol.2018.02.005 102 [24] Arienzo, M., Albanese, S., Lima, A., Cannatelli, C., Aliberti, F., Cicotti, F., Qi, S., and De Vivo, B., 2015 Assessment of the concentrations of polycyclic aromatic hydrocarbons and organochlorine pesticides in soils from the Sarno River basin, Italy, and ecotoxicological survey by Daphnia magna Environmental monitoring and assessment, 187(2), 1–14 doi: 10.1007/s10661-015-4272-5 [25] Narahashi, T., 2010 Neurophysiological effects of insecticides In Hayes’ Handbook of Pesticide Toxicology (pp 799–817) Academic Press doi: 10.1016/B978-0-12-374367-1.00031-8 ... D magna and M macrocopa to evaluate water quality and ecological toxicity [4–6] However, there is little information on the acute toxicity assessment of OCPs on two crustaceans D magna and M macrocopa, ... DISCUSSION Effects of DDT The results of the DDT toxicity assessment on D magna and M macrocopa after 24 h and 48 h are shown in Figure and Table Table showed that the LC50 values on D magna and M macrocopa. .. well contains mL of OCPs, and the control sample well is absent of chemicals Nine individuals of D magna and M macrocopa (24 h of age) were exposed to Tran Thi Thu Huong et al./Vietnam Journal of